This in from Nigel Young who has been struggling to get his shower plate and brew head block off to address the scale issue in his Gaggia Classic...
> Found another tip to remove shower plate holder. Use a bolt same
> thread as shower plate screw, insert and tighten gently till contact
> with internal group head plate then gently frees away. This must be
> the service shop method rather than descaling multiple times. Once out
> scrape away lime scale gently with a penknife, wire brush, dremel disc
> to recover to smooth surface (take care not to damage outer fine
> raised edge) reassemble, flush and job done in under 30 minutes.
Good tip Nigel! The brew block can be a pest to remove if it has been on for
a while -- and there is no need to remove the GASKET if you do not have to --
and definitely no need to do so here.
Be gentle with the method above not to mar the threads of the shower plate!